but in 1996 its original name, Kostroma was restored and it is in active service with the Russian Northern Fleet. The Sierra I class was also fitted with a releasable escape pod for the crew. The pod is covered by a V-shaped casing on the port side of the sail. Project 945A Kondor (Sierra II) The Project 945A has a considerably larger sail which is longer than the Sierra I class. The sail also has a curious flat, square leading edge. The masts are offset on the starboard side to make way for two escape pods in the sail. The starboard side also has a 10-point environment sensor fitted at right angles to the front end of the sail. Also, the Sierra II class has a much larger pod on its after fin. The pod houses the Skat 3 passive very low frequency towed sonar array. Of the two existing submarines of type Sierra II, the Pskov was in overhaul between 2011 and 2015 according to the Russian website Deep storm. The aforementioned website acknowledges activity of Nizhniy Novgorod under the command of Captain 1st Rank Alexey Ananko at in both 2008 and 2013. Both Nizhniy Novgorod and Pskov took part in large exercise in October 2019. Project 945AB (Sierra III) The single submarine of the Project 945AB was laid down in March 1990 but was scrapped in November 1993 before completion. Aborted Barrakuda (Sierra I) modernization Modernization of the Carp and Kostroma of Project 945 for the Russian Navy was anticipated in the 2010s, but in the event, was not completed. A January 2013 contract for refit and recommission of the two submarines was signed with the Zvezdochka Shipyard, Severodvinsk, with the refit expected to take three years. Originally expected that the submarines would be transferred to Zvezdochka before end of April 2013 with the overhaul beginning in summer 2013. Plans included that Zvezdochka would carry out the refit, repair mechanical parts, and replace nuclear fuel and all electrical equipment of the submarines. The submarines were also expected to receive a new sonar, combat information management system (BIUS), the GLONASS navigation system and new armament consisting of the Kalibr cruise missiles. However, in March 2015 it was reported that the final decision on the modernization of submarines Carp and Kostroma'' had not yet been made due to cost issues. Units See also List of Soviet and Russian submarine classes